T-S curves in depths less than about 50 meters in the Labrador Cur- 

 rent water, 75 meters in the mixed water, and somewhat deeper 

 levels in the Atlantic Current water. In addition there are occasional 

 stations where the upper levels of the station belong to one water 

 mass and the lower levels to another water mass. However, the 

 occasions when the measurements at a station have shown a mixture 

 of water from the parent water masses in other than the proportions 

 characteristic of the mixed water have been infrequent. 



The most extensive series of measurements of this region covers the 

 seasons of 1934 to 1941 inclusive. While this 8-year series does not 

 qualify for the establishment of normals, mean values for the 8 years 

 have been used for reference in the absence of better tentative normals. 

 In figure 22 temperature-salinity relationships are given for the Lab- 

 rador Current water, the Atlantic Current water, and the mixed water. 

 The curves for 1950 are shown as solid lines and the 8-year means for 

 the period 1934-41 are shown as broken lines. An inspection of the 

 figure shows the curve for Labrador Current water to be displaced 

 toward the cold side from the mean. The curve for mixed water is 

 seen to be displaced toward the fresh side from the mean and the curve 

 for Atlantic Current water seems to be rotated with respect to the 

 mean, being displaced toward the salty side in upper levels and toward 

 the fresh side at lower levels. 



The deficiency in the West Greenland Current component of the 

 Labrador Current and the almost total absence of Irminger Current 

 water from the West Greenland Current at Cape Farewell in 1949 is 

 considered to be an important source of the change in the Labrador 

 Current. As the Labrador Current is an important contributor in 

 the formation of the mixed water this cause was operative in bringing 

 about the shift in characteristics of the mixed water. Other causes, 

 however, must be sought for the changes in the Atlantic Current water. 



Level for level, at all levels, the density of each of the three water 

 masses was less in 1950 than for the 8-year mean. Neglecting the 

 surface layers, the average decrease amounted to about 0.05 in at from 

 100 to 1,000 meters in the Labrador Current water and the mixed 

 water, and about 0.08 from 400 to 1,000 meters in the Atlantic Cur- 

 rent water. We have here an illustration of the fact that as between 

 temperature and salinity, the former is the controlling factor in the 

 Atlantic Current whereas the latter is the controlling factor in the 

 Labrador Current. Although the temperatures in the Labrador Cur- 

 rent water were subnormal the decrease in salinities was great enough 

 to produce a decrease in density at all levels. In the Atlantic Current 

 water, while the salinities were higher than average in the upper 

 layers the increased average temperatures produced a decrease in 

 density at all levels. In the mixed water the temperatures were lower 

 in the upper levels and higher in the lower levels than is usual; but the 



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